The present invention relates to a new and improved construction of a bearing unit, especially although not exclusively for use in a take-up system for winding a filament, especially a yarn or thread into a package on a bobbin tube.
The present invention also relates to a new and improved construction of a bobbin tube support mechanism or support for a take-up system for winding a filament, especially a yarn or thread into a package on a bobbin tube, and in which take-up system the bobbin tube or package forming thereupon engages a rotatable roll. The bearing unit is advantageously useable in such bobbin tube support mechanism or support.
In its more particular aspects, the present invention specifically relates to a new and improved construction of a filament take-up system for winding a filament, especially a yarn or thread into a package on a bobbin tube and which filament take-up system contains a bobbin tube support mechanism supporting the bobbin tube and the package wound thereupon and urging the bobbin tube or the package wound thereupon into engagement with a rotatable or drive roll.
The roller may be of the grooved drum type adapted to traverse the thread to and fro. Instead, a separate traverse mechanism may be provided in order to enable formation of a cross-wound package. In a preferred arrangement, the mechanism is of the so-called cradle type and has a pair of arms between which the bobbin tube is supported during use. In an alternative arrangement the bobbin tube is supported on a cantilevered stub shaft or spindle.
In filament take-up systems of such type, it is known to support bobbin tube engaging elements in a manner enabling limited movement thereof relative to other parts of the mechanism. There is thus provided a limited degree of adjustment to compensate for misalignments when the bobbin tube is brought into contact with the rotatable or drive roll. One such system is shown, for example, in German Patent Specification No. 1,560,475 and the cognate U.S. Pat. No. 3,286,948, granted Nov. 22, 1966. An alternative system is shown in Swiss Patent No. 339,102, published July 31, 1959.
It has been found, however, that these known systems still do not enable compensation for misalignments so as to produce line contact between the bobbin tube and the rotatable or drive roll. Furthermore, they do not provide damping against the effects of shocks which inevitably arise during formation of cross-wound packages.